scholarly journals Maximum Efficiency Despite Lowest Specific Speed—Simulation and Optimisation of a Side Channel Pump

2019 ◽  
Vol 4 (2) ◽  
pp. 6 ◽  
Author(s):  
Markus Mosshammer ◽  
Helmut Benigni ◽  
Helmut Jaberg ◽  
Juergen Konrad
Keyword(s):  
Numerical Model ◽  
Turbulence Models ◽  
Low Flow ◽  
Maximum Efficiency ◽  
Side Channel ◽  
Main Stage ◽  
Cfd Simulations ◽  
Efficiency Increase ◽  
Computational Fluid Dynamics Cfd ◽  
Specific Speed

Side channel pumps provide high pressure at relatively low flow rates. This comes along with a quite low specific speed and thus with the known disadvantage of a quite poor maximum efficiency. This paper describes the detailed analysis and optimisation of a typical 1-stage side channel pump with an additional radial suction impeller by means of computational fluid dynamics (CFD) simulations. In a first step, the model was successively generated and it was obvious that it has to contain all details including suction impeller and main stage (both 360° models) as well as the pressure housing and all narrow gaps to provide useful simulation results. Numerical simulations were carried out in a stationary and transient way with scale resolving turbulence models to analyse the components in detail. Finally the CFD-simulations were validated with model tests. For the optimisation process it was necessary to generate a reduced numerical model to analyse the effects of more than 300 geometry variations. The findings were then combined to establish the desired objectives. Finally the best combinations were validated again with the full numerical model. Those simulations predict a relative efficiency increase at best efficiency point (BEP) and part load >30% with respect to all given limitations like identical head curve, suction behavior, and dimensions.

A Systematical Study of the Influence of Blade Number on the Performance of a Side Channel Pump

2019 ◽  
Vol 141 (11) ◽  
Author(s):  
Annika Fleder ◽  
Martin Böhle
Keyword(s):  
Experimental Studies ◽  
Numerical Results ◽  
Channel Height ◽  
Side Channel ◽  
Outer Diameter ◽  
Cfd Simulations ◽  
Blade Number ◽  
Performance Curves ◽  
Flow Phenomena ◽  
Computational Fluid Dynamics Cfd

For side channel machines, distinction is made between side channel pumps and peripheral pumps. The blade number of side channel machines has a large influence on the performance of the pump. This is known from several experimental studies. For industrial side channel pumps, the blade number is between 20 and 26, whereas for industrial peripheral pumps, the blade number is much larger (between 36 and 90). In this paper, the influence of the blade number on the performance and the inner flow phenomena of different pumps will be investigated experimentally and numerically. The inner flow of the pump is examined in detail by computational fluid dynamics (CFD) simulations. Flow angles and velocities of the circulation flow between side channel and impeller are considered for different blade numbers. To explain the influences of the blade number, numerical results and theoretical formulas are combined. The experiments are carried out for two different modular side channel pump units, which differ in the side channel height h, the outer impeller diameter da, and the length of the blades l. So, the influence of the blade number can be studied in the context of other parameters like, for example, the relation between blade length and outer diameter of the pump. The obtained numerical results are compared with experimental data. Effects of the blade number on the performance curves of the pumps are shown by experimental and numerical results.

Influence of Gas-Liquid Multiphase-Flow on Acoustic Behavior and Performance of Side Channel Pumps

2017 ◽  
Author(s):  
Sebastian Fleder ◽  
Frank Hassert ◽  
Martin Böhle ◽  
Beate Zientek-Strietz
Keyword(s):  
Multiphase Flow ◽  
Maximum Amount ◽  
Low Flow ◽  
Working Fluid ◽  
Side Channel ◽  
Phase Flow ◽  
Acoustic Behavior ◽  
Centrifugal Pumps ◽  
Two Phase ◽  
Specific Speed

Side-channel pumps (SCP) are a niche product, able to deliver relatively high heads at low flow rates, which corresponds in a low specific speed. They are closing the gap between classical radial centrifugal pumps and positive displacement pumps, combining the advantages of both without having all the negative effects. The hydraulic efficiency of SCP seems low at first sight. But classical centrifugal pumps are often working under part load conditions, when working at this volume flow and specific speed range, which means they are not able to perform at their BEP. This reduces the efficiency of centrifugal pumps and creates a major benefit of SCP, which are able to work in their BEP. The acoustic behavior and the characteristic pulsations and vibrations of a side channel pump are measured with various measurement methods, such as vibrometry, sound level measurement and sound cartography using an acoustic camera. The characteristic vibrations are shown and compared to the characteristic pressure-pulsations of the working fluid. The two-phase liquid-gas flow has, beside the effects on the characteristic curves such as head drop and efficiency reduction, many side effects on the behavior of the pump. This could be acoustical and vibrational effects. When gas is present in the working fluid, the emitted noise from the pump reduces significantly. This effect is shown by sound intensity measurements as well as measurements with an acoustic camera and laser vibrometry and compared to the results for single-phase flow. The maximum amount of gas for the test pump is measured at different rotational speeds. Some theories to improve the maximum amount of gas in the working fluid are presented and the modifications are tested on a test rig. These modifications consist of the idea that a pump without NPSH-impeller could process higher amounts of gas in multiphase-flow conditions. An additional gas outlet hole is added to the pump to allow a phase separation and therefore a better two-phase flow handling of the pump. The effect of these changes on the maximum amount of gas are presented and evaluated.

scholarly journals IMPROVING THE QUALITY OF DESIGNING LOW-FLOW STAGES OF CENTRIFUGAL COMPRESSORS DUE TO VERIFICATION AND VALIDATION OF CALCULATED CFD MODELS

2020 ◽  
Vol 22 (6) ◽  
pp. 48-56
Author(s):  
V.M. Ivanov ◽  
◽  
Yu.V. Kozhukhov ◽  
A.M. Danylyshyn ◽  
◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Numerical Model ◽  
Low Flow ◽  
Centrifugal Compressors ◽  
Labyrinth Seals ◽  
Design Quality ◽  
Cfd Models ◽  
Computational Fluid Dynamics Cfd

The quality of the produced centrifugal compressors largely depends on the design quality of the flow path. In order to carry out high-quality design of low-flow stages of centrifugal compressors, in this work, a numerical model of a low-flow stage is verified and validated, which are based on modern methods of computational fluid dynamics - CFD (computational fluid dynamics) as part of CALS technologies. In the numerical model of the step, clearances and labyrinth seals were modeled. The issues of using intergrid interfaces, application of turbulence and roughness models are considered. The obtained settings of the numerical model were used to validate seven model stages for the range of the optimal conditional flow rate Φopt = 0.008-0.018 at Mu = 0.785-0.804. The simulation results were compared with experimental data.

scholarly journals COMPUTATIONAL PREDICTION OF A PROPELLER PERFORMANCE IN OPEN WATER CONDITION

SINERGI ◽  
2020 ◽  
Vol 24 (2) ◽  
pp. 163
Author(s):  
Ahmad Fitriadhy ◽  
N. Amira Adam ◽  
CJ. Quah
Keyword(s):  
Cfd Simulation ◽  
Open Water ◽  
Computational Prediction ◽  
Maximum Efficiency ◽  
Cfd Simulations ◽  
Water Condition ◽  
Pitch Ratio ◽  
Computational Fluid Dynamics Cfd ◽  
Preliminary Study ◽  
Propeller Performance

In presence of hydrodynamics phenomena occur surrounding propeller evidently affects on accuracy’s prediction of thrust, torque and its efficiency. To achieve the objective, a Computational Fluid Dynamics (CFD) simulations approach is then proposed to obtain a reliable prediction of the thrust (KT), torque (KQ) and efficiency (η) coefficients in open water condition. The effect of various blade numbers associated with constant propeller revolution (RPM=1320) and pitch ratio (P/D=1.0); are performed within the range of advance ratio from 0.1J1.0. The results revealed that the increase of blade number from Z=3 to 5 was proportional with the increase of thrust (KT) and torque (KQ) coefficients; meanwhile, it was reduced the maximum efficiency (η) that possibly lead to downgrade the propeller performance. It should be noted here, the propeller with three blade numbers (Z=3) provide the highest efficiency (η) up to 78.8% at J=0.9. These CFD simulation results are very useful as a preliminary study of propeller characteristics.

Isothermal Boundary Condition at Casing Applied to the Rotor 37 Transonic Axial Flow Compressor

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Dario Bruna ◽  
Mark G. Turner
Keyword(s):  
Boundary Condition ◽  
Axial Flow ◽  
Low Flow ◽  
Cfd Simulations ◽  
Data Set ◽  
Isothermal Boundary ◽  
Flow Test ◽  
Total Temperature ◽  
Computational Fluid Dynamics Cfd ◽  
Flow Compressor

Computational fluid dynamics (CFD) simulations are presented with an isothermal boundary condition at the casing for running NASA Rotor 37. The casing temperature is set to the inlet total temperature. Relative to the adiabatic simulations, the comparison to experimental efficiency is much improved for the 100% speed line. The efficiency difference between the isothermal and adiabatic solutions is about 1%, and matches the low-flow test condition. The profiles of total temperature with the isothermal boundary condition match the data near the casing. The adiabatic simulation has a total temperature overshoot that has been consistently part of any data comparison of CFD with this data set, and is typical of most compressor calculations. The efficiency profile has a similar improvement in matching the data because of its relationship to temperature. The real rig is not isothermal at the casing and may require more complex simulations such as a conjugate heat transfer approach to truly match the physics. However, the isothermal boundary condition is more accurate and more realistic than the adiabatic boundary condition.

Performance enhancement of Savonius wind turbine by blade shape and twisted angle modifications

2021 ◽  
pp. 095765092098794
Author(s):  
Ahmed M Nagib Elmekawy ◽  
Hassan A Hassan Saeed ◽  
Sadek Z Kassab
Keyword(s):  
Wind Turbine ◽  
Performance Enhancement ◽  
Three Dimensional ◽  
Turbulence Models ◽  
Vertical Axis ◽  
Cfd Simulations ◽  
Sliding Mesh ◽  
Blade Shape ◽  
Rotor Shape ◽  
Twisting Angle

Three-dimensional CFD simulations are carried out to study the increase of power generated from Savonius vertical axis wind turbines by modifying the blade shape and blade angel of twist. Twisting angle of the classical blade are varied and several proposed novel blade shapes are introduced to enhance the performance of the wind turbine. CFD simulations have been performed using sliding mesh technique of ANSYS software. Four turbulence models; realizable k -[Formula: see text], standard k - [Formula: see text], SST transition and SST k -[Formula: see text] are utilized in the simulations. The blade twisting angle has been modified for the proposed dimensions and wind speed. The introduced novel blade increased the power generated compared to the classical shapes. The two proposed novel blades achieved better power coefficients. One of the proposed models achieved an increase of 31% and the other one achieved 32.2% when compared to the classical rotor shape. The optimum twist angel for the two proposed models achieved 5.66% and 5.69% when compared with zero angle of twist.

Regenerative flow pumps, blowers and compressors – A review

2021 ◽  
pp. 095765092110181
Author(s):  
M Sreekanth ◽  
R Sivakumar ◽  
M Sai Santosh Pavan Kumar ◽  
K Karunamurthy ◽  
MB Shyam Kumar ◽  
...  
Keyword(s):  
Quantitative Data ◽  
Research Work ◽  
Future Research ◽  
Performance Parameters ◽  
The World ◽  
Working Principle ◽  
Computational Fluid Dynamics Cfd ◽  
Specific Speed ◽  
Regenerative Flow ◽  
Product Description

This paper presents a detailed and objective review of regenerative flow turbomachines, namely pumps, blowers and compressors. Several aspects of turbomachines like design and operating parameters, working principle, flow behaviour, performance parameters and analytical and Computational Fluid Dynamics (CFD) related details have been reviewed and summarized. Experimental work has been put in perspective and the most useful results for optimized performance have been presented. Consolidated plots of specific speed-specific diameter have been plotted which can be helpful in the early stages of design. Industrial outlook involving details of suppliers from various parts of the world, their product description and applications too are included. Finally, future research work to be carried out to make these machines widespread is suggested. This review is targeted at designer engineers who would need quantitative data to work with.

scholarly journals Using CFD to Evaluate Natural Ventilation through a 3D Parametric Modeling Approach

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2197
Author(s):  
Nayara Rodrigues Marques Sakiyama ◽  
Jurgen Frick ◽  
Timea Bejat ◽  
Harald Garrecht
Keyword(s):  
Natural Ventilation ◽  
Parametric Modeling ◽  
Cfd Simulations ◽  
3D Design ◽  
Post Process ◽  
Test House ◽  
Model Set ◽  
Computational Fluid Dynamics Cfd ◽  
Set Up ◽  
Passive Strategy

Predicting building air change rates is a challenge for designers seeking to deal with natural ventilation, a more and more popular passive strategy. Among the methods available for this task, computational fluid dynamics (CFD) appears the most compelling, in ascending use. However, CFD simulations require a range of settings and skills that inhibit its wide application. With the primary goal of providing a pragmatic CFD application to promote wind-driven ventilation assessments at the design phase, this paper presents a study that investigates natural ventilation integrating 3D parametric modeling and CFD. From pre- to post-processing, the workflow addresses all simulation steps: geometry and weather definition, including incident wind directions, a model set up, control, results’ edition, and visualization. Both indoor air velocities and air change rates (ACH) were calculated within the procedure, which used a test house and air measurements as a reference. The study explores alternatives in the 3D design platform’s frame to display and compute ACH and parametrically generate surfaces where air velocities are computed. The paper also discusses the effectiveness of the reference building’s natural ventilation by analyzing the CFD outputs. The proposed approach assists the practical use of CFD by designers, providing detailed information about the numerical model, as well as enabling the means to generate the cases, visualize, and post-process the results.

scholarly journals The Problem of Accounting for Heat Exchange between the Flow and the Flow Part Surfaces When Modeling a Viscous Flow in Low-Flow Stages of a Centrifugal Compressor

2020 ◽  
Vol 10 (24) ◽  
pp. 9138
Author(s):  
Sergey Kartashov ◽  
Yuri Kozhukhov ◽  
Vycheslav Ivanov ◽  
Aleksei Danilishin ◽  
Aleksey Yablokov ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Exchange ◽  
Centrifugal Compressor ◽  
Calculation Model ◽  
Flow Coefficient ◽  
Low Flow ◽  
Relative Width ◽  
Adiabatic Wall ◽  
Flow Part ◽  
Computational Fluid Dynamics Cfd

In this paper, we review the problem of accounting for heat exchange between the flow and the flow part surfaces when creating a calculation model for modeling the workflow process of low-flow stages of a centrifugal compressor using computational fluid dynamics (CFD). The objective selected for this study was a low-flow intermediate type stage with the conditional flow coefficient Փ = 0.008 and the relative width at the impeller exit b2/D2 = 0.0133. We show that, in the case of modeling with widespread adiabatic wall simplification, the calculated temperature in the gaps between the impeller and the stator elements is significantly overestimated. Modeling of the working process in the flow part was carried out with a coupled heat exchanger, as well as with simplified accounting for heat transfer by setting the temperatures of the walls. The gas-dynamic characteristics of the stage were compared with the experimental data, the heat transfer influence on the disks friction coefficient was estimated, and the temperature distributions in the gaps between disks and in the flow part of the stage were analyzed. It is shown that the main principle when modeling the flow in low-flow stage is to ensure correct temperature distribution in the gaps.

Sign in / Sign up

Export Citation Format

Share Document